COSMAEIUM. 5 



Var. tumidum Wolle. (PI. XCVII, figs. 2, 3.) 



C. Botrytis var. tumidum Wolle, Desm. U. S. 1884-, p. 75, t. 17, f. 3-5 

 [figures not accurate] ; Schmidle in Ber. Deutsch. Botan. Ges. x, 1892, 

 p. 210, t. 11, f. 13-14 ; Beitr. Algenfl. Schwarzwald. u. Kheineb. 1893, 

 p. 99, t. 4, f . 25 [figure not good] ; West & G. S. West, Alg. S. England, 

 1897, p. 490 ; Freshw. Alg. Orkneys and Shetlands, 1905, p. 21 ; Further 

 Contrib. Plankton Scott. Lochs, 1905, p. 484. 



C. Subbotrytis Schmidle, Alg. Bern. Alp. 1894, p. 93. 



Semicells with central tumour causing an inflation 

 on each side of the vertical view ; granules of the 

 central tumour larger than the other granules, and 

 with a very irregular disposition ; often with one large 

 granule adjacent to the isthmus. 



Zygospore exactly as in the type. 



Length 65-85 ft ; breadth 50-68 ^ ; breadth of 

 isthmus 17-20 jit; thickness 34-38 ft. 



ENGLAND.- -Epping Forest, Essex ! Xear Goring, 

 Oxfordshire (with zygospores) ! 



SCOTLAND.- -Inverness ! Lewis, Outer Hebrides ! 

 Shetlands ! Plankton of Loch Shiel, L. Cuthaig ! 



Geutjr. Distribution.- -Germany. Australia. United 

 States. 



We see no justification for the separation of this variety as 

 a species distinct from C. Botrytis. It differs from the type 

 only in the slight central tumour adorned with granules of a 

 rather larger size than the other granules of the cell- wall. 



o o 



Var. gemmiferum (Breb.) Korclst. (PL XCVII, 



fig. 4.) 



Cosmarium gemmiferum Breb. Liste Desm. 1856, p. 301 ; Arch, in Pritch. 



Infus. 1861, p. 733; Eabenh. Flor. Europ. Alg. 1868, III, p. 159 ; Lund. 



Desm. Suec. 1871, p. 26 ; Xordst. in Wittr. & Xordst. Alg. Exsic. 1886, 



no. 826 ; De Toni, Syll. Alg. 1889, p. 985. 

 C. Botrytis var. gemmiferum (Breb.) Nordst. Bornli. Desm. 1888, p. 191 ; 



G-utw. Flor. Glonow Okolic Lwowa, 1891, p. 52. 

 Ursiiiella gemmifera Kuntze, Revis. gen. plant. 1891, p. 924. 



Semicells with a central granulated tumour sur- 

 rounded by a smooth area of small extent, towards 

 which the surrounding granules are slightly reduced 

 in size ; vertical view with a small inflation on each side. 



Length 65-89 ^ ; breadth 55-72 //, ; breadth of 

 isthmus 14-24 ^ ; thickness 35-48 {JL. 



